Middle ear stiffness reduces low-frequency gain while added mass reduces high-frequency gain

Evidence

Changes to the outer and middle ear structures can have a direct influence on their transmission properties. In particular, middle ear disorders such as otosclerosis and otitis media affect the stiffness of the ossicular chain in the early stages and then the mass in the later stages. Increasing the stiffness of the middle ear system primarily reduces the gain provided in the low frequencies, whereas increasing the mass mostly reduces the gain provided in the high frequencies. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 215

Categorization

• QUESTION: Worth chasing: what specific audiogram shapes do otosclerosis vs. otitis media produce at early vs. late stages, and how do clinicians distinguish them?
• corroborated: 2 independent passages support this claim — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 215